Work piece guide system

ABSTRACT

A system for accurately controlling and guiding the edge portions of one or more flexible fabric work pieces as they are being fed to a sewing machine stitching zone by applying a biasing or torque force to the work pieces. The torque is responsive to a linear force applied by the feed dogs and to frictional forces applied at pinch points spaced upstream and laterally of the feed dogs which linear force urges the edges of the work pieces into engagement with a guide member for maintaining a line of stitching a predetermined distance away from the edge of each work piece.

' United States Patent i 91 Bryan et al. v Feb. 26, 1974 WORK PIECE GUIDE SYSTEM [56] References Cited [75] Inventors: Carney J. Bryan, Greensboro; FOREIGN PATENTS, 0R APPLICATIONS James B. Fulp, Summerfield, both 519,947 4/1940 Great Britain 112/153 of NC.

[73] Assignee: Blue Bell, Inc., Greensboro, NC. Primary Exammer Auen Knowles 22 Filed: Dec. 26, 19.72 57 ABSTRACT [21] Appl. No.: 318,623 A system for accurately controlling and guiding the edge portions of one or more flexible fabric work [63] C Related Azp g r ro g 26 1972 pieces as they are being fed to'a sewing machine g g i N stitching zone by applying a biasing or torque'force to fi'ggz 5 g g g o the work pieces. The torque is responsive to a linear a an 9 force applied by the feed dogs and to frictional forces applied at pinch points spaced upstream and laterally [52] Cl 226/15 of the feed dogs which linear force urges the edges of 51] Int Cl o 35/10 the work pieces into engagement with a guide member [58] Fieid 198 197 for maintaining a line of stitching a predetermined distance away from the edge of each work piece.

10 Claims, 7 Drawing Figures PATENTE FEM-619.74

saw 1 or 2 FIG.I

INVENTORS CARNEY J. BRYA N JAMES B. FU LP FIG.2'

oHorney PAIENTEUFEBZBIQH 3.794.230

sum 2 0F 2 mm. m

FIG 7 INVENTORS CARNEY J. BRYAN JAMES B. FULP afforn ey WORK PIECE GUIDE SYSTEM This is a continuation of application Ser. No. 221,109, now abandoned filed Jan. 26, I972, which was a continuation application of Ser. No. 877,364, nowabandoned filed Nov. I7, 1969.

BACKGROUND, BRIEF SUMMARY AND OBJECTS OF THE INVENTION This invention relates to a system for automatically guiding and controlling the movement of one or more work pieces to be operated upon through an operating zone.

More particularly, the invention relates to an automatic feed control system for fabrics or similar materials for maintaining one or more work pieces to be fed upon a linear feeding line or path conforming to the edge or contour of the work piece to place a line of stitches at a predetermined distance from the edge of the fabric. I

Although the invention is of special use in conjunctionwith sewing machines, the basic concepts of the invention are susceptible to other uses wherein fabriclike material is fed past an operatingpoint or tool to guide the fabric along a predetermined path of travel.

The conventional manner of feeding material to a sewing machine -is manually to align one or more plies of material with the feed dogs of the machine. The machine operator must then manually align and guide the material being advanced to produce a straight line of stitches. If a curved line of stitches is desired, the material must be manually guided with sewing and orientation of the material.

The guiding assembly of the present invention for automatically controlling movement of the material ineludes a plurality of superposed plates adapted to receive a single ply of fabric between adjacent plates. Each ply of material is clamped between or pinched against one or more plates at points located upstream and to one side of the flow of material to the machine stitching zone. As linear motion is imparted to thematerial by the sewing machine feed dogs, the clamping or pinching effect applied to each layer of material within the guide assembly tends to hold the material, thus resulting in a sliding movement of the material located upstream of thestitching zone to a location with the edges thereof abutting the stopor limiting surface. The edges of the material are maintained in engagement with the abutting or stop surface for aligning the edges of two or more plies of material, even when the material is curved or contoured, such that a line of uniform stitches are maintained a predetermined distance from the edges of the fabric or material.

Oneof the primary objects of the invention is the provision of a guiding assembly for accurately aligning and controlling the edge portions of one or more plies of fabric as they are being fed to the stitching zone of a sewing-machine.

An important feature of the invention is the provision of a guide assembly for directing superposed plies of fabric to a stitching zone and insuring the desired stitching performance without significant control by an operator.

Another feature of the invention is the provision o rial and results in an improved finished product by accurately positioning and aligning the edges of the material.

Still another feature of the invention is a fabric guide system for increasing production, and for reducing expense since less skill is required to operate the sewing machines.

Other features and advantages will be readily apparent to those skilled in the art during the course of the following description of the invention which sets forth preferred embodiments only without limiation.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front elevational view of a sewing machine and support structure therefor, with the fabric guiding apparatus of the present invention positioned thereon.

FIG. 2 is a fragmentary side elevational view illustrating the relationship of the guiding apparatus with respect to the sewing machine;

FIG. 3 is an enlarged top planview of the guiding ap paratus of FIGS. 1 and 2;

FIG. 4 is an enlarged, fragmentary, front elevational view of the guiding apparatus of FIG. 1 illustrating the relationship of the fabric being guided thereby, with respect to the separator plates;

FIG. 5 is a top plan view of the separator plates and fabric edge stop member, having fabric guided thereby, positioned-with respect to the sewing machine fabric advancing and stitching zone;

FIG. 6 is an isometric view of a modified fabric guiding apparatus adapted to be positioned upon a machine support structure; and f FIG. 7 is a top plan view of the modified fabric guiding apparatus of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, FIG. 1 illustrates a sewing machine 10, having a fabric support surface 11, which is mounted on a table top or other support structure 12 of conventional form. Thread isdirected from suitable thread supply sources over a conventional tension mechanism 14 into-one or more needles, not shown,

provided at the stitching zone 16. Fabric feed dogs 18 are located in the stitching zone 16 for feeding the work at a predetermined rate in the direction of the arrow A in FIG. 5. The sewing machine 10 may be provided with a conventional trimmer or cutter 20, shown diagrammatically in FIG. 5, for trimming off the rough edges, of the fabric during and slightly in advance of the sewing operation. The cutter may be adjusted to trim the fabric at various distances from the line of sewing.

A guide assembly 22 for controlling the alignment and proper advancing movement of one or more material work pieces is adjustably mounted upon the machine support structure. The guide assembly 22 is mounted upon a bracket 24 secured to support 12 by fasteners 26, and may be pivoted to an inoperative position shown in dotted outline form in FIG. 2.

Guide assembly 22 includes a series of plates 28, 30, 32 which are secured to a normally vertically oriented support plate 34 which is mounted upon bracket 24.

apparatus for guiding aligned plies of flexible material 42 may be provided between the plates 28, 30, 32 for v adjustably positioned longitudinally of bracket 24 by means of studs 36, 36 which are threadably received within plate 34, and maintained in position by nuts 38, 38 mounted thereon. I

A tensioning mechanism 44 is provided intermediate the length of plates 28, 32 for normally biasing each plate into engagement with an adjacent plate. The tensioning mechanism 44 includes a member 46 threaded throughout the length thereof having nuts 48 located adjacent opposite end portions. The member 48 extends through enlarged openings 50 and outer plates 28 and 32, and is threadably received within an opening 52 in intermediate plate 30. Springs 54, which surround member 46, bias plates 28, 32 toward lower plate 32 which is fixed to plate 34. The spring biasing force applied to each of plates 28 and 30, and consequently to material 56 positioned intermediate to plates 28,30

- and/or plates 30, 32 can be varied by rotation of nuts As can be observed most clearly from FIGS. 1 and 2, the lowermost plate 32 is relatively flat while the ends of plates 28 and 30, remote from fastener 40, are slightly bowed or curved. The plates 28, 30 are curved both longitudinally and transversely adjacent the outermost ends thereof to provide contact points or pinch points 58 and 60 between plates 28, 30 and 30, 32, respectively. As shown in FIG. 5, the contact points 58, 60 are offset relative to each other and apply pinching or clamping forces to material positioned between the plates. The edge portionsof plates 28, 30, 32 are tapered and rounded somewhat to facilitate positioning of material 56 between adjacent plates.

Additionally, the guide assembly 22 is provided with fluid actuated cylinders 62, 64.for spreading the plates 28, 30, 32 to facilitate the insertion of material 56 thherebetween. The cylinders 62, 64 are connected to a remote valve mechanism, not shown, through flexible lines 66, 68. Cylinders 62 and 64 are fixed to plates 28 and 32, respectively, by fasteners 70. Fluid-actuated plunger 72 passes through opening 74 and plate 28 and is adapted to bear against central plate 30 as shown in FIG. 4. Similarly, plunger 36 passes through opening 78. in plate 32 for engagement with plate 30. Normally the plates 28, 30, 32 are urged toward engagement with v each other adjacent contact points 58 and 60 by springs 54, 54 as shown in FIGS. 1 and 2. However, upon actuation of plungers 72, 76 the plates are spread apart as shown in FIG. 4'. Since lower plate 32 and cylinder 64 are fixed with respect to plate 34, displacement of plunger 76 urges central plate 30 and threaded member 46 upwardly compressing lowermost spring 54. Furthermore, displacement of plunger 72 into engagement with central plate 30 serves to pivot plate 28 upwardly thus compreesing the uppermost spring 54.

An arcuate plate member 80, positioned adjacent arcuate surfaces 82 on each of plates 28 and 30, serves as an edge guide for material being advanced tothe stitching zone 16. Arcuate guide member 80 can be adjustably positioned longitudinally with respect to plates 28, 30, 32 on bracket 84. The bracket 84, which is fixed relative to lower plate 32, has a slot 88 provided 4 therein for slidably receiving fasteners 86 which are threadably received within member 88.

-In operation of the guide assembly, the sewing machine presser foot 90 is raised and plates 28, 30, 32 are opened by actuating plungers 72, 76. Material 56 to be sewn then is insertedbetween the plates, as shwon by FIGS. 4 and 5, until the edge portions thereof roughly engage arcuate stop member 80. Fluid pressure within cylinders 62, 64 is relieved permitting plates 28, 30, 32 to close thus gripping one layer of the material 56 at point 58 and gripping the other layer 56 at point 60. Also, the presser foot 90 is lowered to a sewing position. During the sewing operation the edges of material 56 are accurately and automatically guided and aligned as they are displaced in a directed path of travel through the stitching zone 16. Cutter 20 trims off any rough edge portions of the material being advanced through the stitching zone.

The edge portions of the fabric material 56, 56 are properly aligned and guided through the cooperation of feed dogs 18, plates 28, 30, 32, pinch points 58, 60 and stop member 80. A torque force is applied to each layer of material'56 in the direction of arrow B for urging the material edges into engagement with stop member 80. Stop member and contact points 58, 60 arelocated upstream and laterally of the stitching zone 16. Thus it can be seen that the frictional forces applied to material 56 at points 58, 60, as the material is advanced by feed dogs 18 in direction A, applies a biasing actionor torque to the material in the direction of arrow B thus sliding the material edges against stop member 80. The material between the stop member 80 and pinch points 58, 60 is prevented from buckling and is maintained in a relatively flattened condition by plates 28, 30, 32, and

the edge portions of each layer of material are moved independently of each other in the direction of arrow B until they abut stop member 80. As a result, the guide assembly 22 assures movement of the edge portions of one or more pieces of material to be sewn along the proper path to the stitching zone 16 even when the edges of the material are contoured.

FIGS. 6 and 7 illustrate a modified embodiment of the guide assembly. The modified-assembly 10 includes a series of spaced plates 102, 104, 106 secured in as sembled relation by fasteners 108, 110. Located between plates 102, 104, and 106 are spacer plates 112 and 114. each having an arcuate edge guiding surface 116 for directing material 56 to the stitching zone 16 of a sewing machine. Spacer plates 112, 114 function in a manner similar to stop member 80 of the embodiment of FIGS. 1 through 5 to guide the edges of material 56.

Outermost plates 102 and 106 have portions removed therefrom to form notches 126, 128 for receiving wire spring member 118, 120. The spring members which are supported adjacent opposite end portions of fastener 108 are biased toward plate 104 such that the end portions 122, 124 engage the top and bottom sides thereof. Thus it can be seen that material 56 positioned between plates 102, 104 and plates 104, 106 will be gripped or pinched between adjacent spring member end portions 122, 124 and plate 104.

As material 56 is advanced in the direction of arrow A the edge portions thereof are forced to the right, as shown by FIG. 7, until they abut the curved surfaces 1 16 of spacer plates 112, 114. The material 56. moves into engagement with surfaces 116 since the spring end portions 122, 124, applyingfrictional forces separately to each material layer, are located upstream and to one side of the stitching zone 16 similarly to contact points 58 and 60 in the embodiment of FIGS. 1 through 5.

Plates 102, 104, 106 are of different lengths and may be curved slightly adjacent the end portions remote from fastener 108 in order to facilitate insertion of material 56 therebetween. The guide assembly 100 can be adjustably positioned on a sewing machine support structure by the bracket 130 having a slot 132 provided therein for receiving conventional fasteners, not shown. 1

The present invention further provides a means for accurately controlling the longitudinal alignment of two or more superposed plies of material as they are advanced to a stitching zone or other work station. Normally in advancing superposed plies of material to a stitching zone, the feed dogs tend to advance the low- The advancing plies of material are controlled to main-,

tain them in longitudinally aligned relationship by varying forces applied individually to each ply of material to retard advancement to the stitching zone. For example, the tension or retarding effect applied to the lowermost ply of material by plates 30, 32 and contact point 60 may be increased by adjusting the pressure applied by spring 54 such that the plies of material are advanced at the same rate.

We claim:

l. The method of controlling and aligning edge portions of flexible material comprising the steps of: advancing material by applying a prescribed linear force to the material, clamping the material with a predetermined force to apply a torque to the material as the material is advanced, displacing the material in a preselected direction in response to the torque applied thereto, and limiting the displacement of the materialresponsive to the torque beyond a specified location to guide edge portions of the material.

2. The method as defined in claim 1, wherein the material is clamped at a prescribed locationspaced upstream and laterally of the linear force.

3. The method as defined in claim 1, and further including the step of maintaining portions of the material adjacent the guided edge portions in an unbuckled and substantially flattened condition.

4. Apparatus for controlling and guiding an edge portion of at least one work piece comprising: means for supportingand retaining a work piece in a generally flattened and unbuckled condition adjacent an edge portion to be guided, means for applying a force to a work piece sufficient to displace the work piece edge portion in predetermined direction, and means for limiting displacement of a work piece in said predetermined direction by engaging the edge portion thereof.

' multaneously and independently.

6. Apparatus as defined in claim 4, said supporting and retaining means including a plurality of superposed plates, and adjacent plates being positioned to receive a work piece therebetween.

7. Apparatus as defined in' claim 4, wherein said force applying clamping means includes arcuate means biased into engagement with the work pieces at prescribed locations.

8. Apparatus as defined in claim 4, wherein said work piece limiting means includes an adjustable stop member for restricting displacement of one or more 'work pieces beyond a predetermined location. i

9. Apparatus as defined in claim 4, wherein said supporting and retaining means and said force applying means cooperate with said displacement restricting pieces therebetween. 

1. The method of controlling and aligning edge porTions of flexible material comprising the steps of: advancing material by applying a prescribed linear force to the material, clamping the material with a predetermined force to apply a torque to the material as the material is advanced, displacing the material in a preselected direction in response to the torque applied thereto, and limiting the displacement of the material responsive to the torque beyond a specified location to guide edge portions of the material.
 2. The method as defined in claim 1, wherein the material is clamped at a prescribed location spaced upstream and laterally of the linear force.
 3. The method as defined in claim 1, and further including the step of maintaining portions of the material adjacent the guided edge portions in an unbuckled and substantially flattened condition.
 4. Apparatus for controlling and guiding an edge portion of at least one work piece comprising: means for supporting and retaining a work piece in a generally flattened and unbuckled condition adjacent an edge portion to be guided, means for applying a force to a work piece sufficient to displace the work piece edge portion in predetermined direction, and means for limiting displacement of a work piece in said predetermined direction by engaging the edge portion thereof.
 5. Apparatus as defined in claim 4, wherein the edge portions of a plurality of work pieces may be guided simultaneously and independently.
 6. Apparatus as defined in claim 4, said supporting and retaining means including a plurality of superposed plates, and adjacent plates being positioned to receive a work piece therebetween.
 7. Apparatus as defined in claim 4, wherein said force applying clamping means includes arcuate means biased into engagement with the work pieces at prescribed locations.
 8. Apparatus as defined in claim 4, wherein said work piece limiting means includes an adjustable stop member for restricting displacement of one or more work pieces beyond a predetermined location.
 9. Apparatus as defined in claim 4, wherein said supporting and retaining means and said force applying means cooperate with said displacement restricting means to align and control independently a plurality of work pieces.
 10. Apparatus as defined in claim 6, further including means for displacing said superposed plates to an opened position to facilitate the insertion of work pieces therebetween. 